This invention relates to an ink-jet printing method and apparatus for printing an image by jetting ink onto a printing medium from an ink-jet print head, as well as to a printing system which includes this apparatus.
An automatic vending machine that has recently become available is adapted to print an image on a medium such as a seal and sell the seal, wherein the image is a combination of, say, a photograph of the face of the customer and a digital image. By printing a color illustration and characters along with a photograph of one""s face, such an automatic vending machine that sells these printed images provides the printed image with added value. Such printed images are utilized as name cards for personal use and there is growing demand for the capability to print the name of the customer on a color seal. It is desired that the printing apparatus used in such an automatic vending machine be capable of performing color printing for the purpose of raising the added value of the printed item and that the apparatus be capable of printing at high speed in order to meet the demands of a large number of customers.
An ink-jet printer, which has a color printing capability, is low in cost and provides a high-quality color image, has been contemplated for use as the printing apparatus in an automatic vending machine of the type mentioned above. However, such an ink-jet printer capable of printing a color image is provided with four ink-jet heads for the colors yellow, magenta, cyan and black, for example, and it is necessary to clean the ink-jet heads (perform a recovery process) before printing processing starts in order that images having stable image quality may be obtained at all times. In particular, when such a printer is employed in the above-described automatic vending machine, the times when the machine is used vary widely and it is necessary, therefore, that the head recovery process always be performed prior to the start of printing. Accordingly, whenever a single image is printed, the time needed to perform recovery process is greater than that for printing processing. This means that when processing for printing a plurality of images is executed, a very long period of time is required because the recovery process is executed each time an image is printed. This lengthens the time the customer must wait for images to be printed and causes a decline in the ability to service customers.
Accordingly, an object of the present invention is to provide an ink-jet printing method and apparatus, as well as a printing system that includes this apparatus, wherein the time needed for printing can be greatly curtailed by minimizing the number of times recovery process is performed for the ink-jet heads.
Another object of the present invention is to provide an ink-jet printing method and apparatus, as well as a printing system that includes this apparatus, wherein when a plurality of images are printed in succession, for example, recovery process is performed whenever a prescribed number of images is printed, thereby making it possible to greatly curtail total printing time needed for printing.
A further object of the present invention is to provide an ink-jet printing method and apparatus, as well as a printing system that includes this apparatus, wherein if the time required to accept succeeding image data following the completion of an image printing operation is greater than a predetermined period of time, recovery process for the ink-jet print head is executed at the start of the next printing operation, thereby reducing the number of times recovery process is performed and shortening the time needed for printing.
A further object of the present invention is to provide an ink-jet printing method and apparatus, as well as a printing system that includes this apparatus, wherein recovery process for the ink-jet print head is performed at the start of the next printing operation and transport of the printing medium is halted when the time required to accept succeeding image data following the completion of an image printing operation exceeds a predetermined period of time, or only when a predetermined number of sheets is printed, thereby making it possible to greatly curtail total printing time.
A further object of the present invention is to provide an ink-jet printing method and apparatus, as well as a printing system that includes this apparatus, wherein when printing processing does not start within a first predetermined period of time following the completion of an image printing operation, capping of the ink-jet head is carried out, and if elapsed time from the capping operation following the preceding printing operation is greater than a second predetermined period of time at the moment development of the next item of print data ends, recovery process for the ink-jet head is performed, thereby preventing a decline in printing quality as caused by drying of the ink-jet head and allowing total printing time to be shortened.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.